Centrifugal pump

ABSTRACT

A housing of a centrifugal pump includes a fluid inlet, a fluid outlet, and an accommodation chamber. An impeller of the pump is disposed in the accommodation chamber and includes at least one venthole axially penetrating the impeller. A drive member is fixed to one side of the housing and corresponds to the impeller for providing electromagnetic force required for rotation of the impeller. A central shaft penetrates the center of the impeller and axially extends to the drive member.

BACKGROUND

The invention relates to a centrifugal pump, and in particular to a centrifugal pump with a vent structure enabling removal of air therefrom.

Referring to FIG. 1, a conventional centrifugal pump comprises a housing 1, an impeller 2, a stator 3, and a central shaft 4. The stator 3 is able to activate the impeller 2 rotating with the central shaft 4.

The housing 1 comprises an accommodation chamber in which the impeller 2 is disposed. The housing 1 further comprises a water inlet 10 and a water outlet 12. Water flows into the centrifugal pump via the water inlet 10. In another aspect, water flows out of the centrifugal pump along the rotational direction of the impeller 2 and via the water outlet 12.

The impeller 2 comprises a rotating portion 20 and a plurality of blades 22 disposed thereon.

The stator 3 is disposed under the impeller 2 and coupled to the rotating portion 20, activating the impeller 2 by electromagnetic force when electricity is applied thereto. The central shaft 4 axially penetrates the center of the impeller 2 and extends to the stator 3.

The water inlet 10, water outlet 12, and accommodation chamber of the housing 1 are connected to and communicated with one another. During operation of the conventional centrifugal pump, water flows to the impeller 2 via the water inlet 10 and obtains kinetic energy by rotation of the impeller 2. The water then flows out of the centrifugal pump via the water outlet 12 by centrifugal force provided by the blades 22 of the impeller 2.

Nevertheless, at startup or during operation of the conventional centrifugal pump, air inevitably enters the centrifugal pump, adversely affecting the pumping pressure and causing the impeller 2 to idle. Air binding is thus generated.

Moreover, when the centrifugal pump operates in the presence of air and water, rotational balance of the impeller 2 is adversely affected to cause noise. Furthermore, air erosion is easily generated in the centrifugal pump. Namely, air bubbles in the centrifugal pump break and strike the impeller 2 during rapid movement of the water and the air bubbles, ablating the surfaces of the blades 22 of the impeller 2 and thereby causing damage thereto.

SUMMARY

Accordingly, an embodiment of the invention provides a centrifugal pump comprising a housing, an impeller, a stator, and a central shaft. The housing comprises a fluid inlet, a fluid outlet, and an accommodation chamber. The fluid inlet, fluid outlet, and accommodation chamber are connected to and communicated with one another. The impeller is disposed in the accommodation chamber and comprises at least one venthole axially penetrating the impeller. The stator is fixed to one side of the housing and corresponds to the impeller, providing electromagnetic force required for rotation of the impeller. The central shaft penetrates the center of the impeller and axially extends to the stator.

The impeller further comprises a rotating portion and a plurality of blades. The venthole axially penetrates the rotating portion, and the blades are formed on a surface of the rotating portion.

The housing further comprises a top cover and an outer frame. The accommodation chamber is between the top cover and the outer frame. The fluid inlet and fluid outlet are formed and extend in the top cover. Fluid flows into the centrifugal pump via the fluid inlet and out of the centrifugal pump via the fluid outlet along the rotational direction of the impeller.

The outer frame surrounds the stator, preventing the fluid from entering the drive member.

The housing further comprises a base opposite to the top cover, and the stator is fixed to the base.

Accordingly, when the centrifugal pump operates, air therein is expelled via the venthole, thereby decreasing pumping pressure loss, air binding, noise, vibration, and air erosion.

Another embodiment of the invention provides a centrifugal pump comprising a housing, an impeller, a stator, and a central shaft. The housing comprises a fluid inlet, a fluid outlet, and an accommodation chamber. The impeller is disposed in the accommodation chamber. The stator is fixed to one side of the housing and corresponds to the impeller, providing electromagnetic force required for rotation of the impeller. The central shaft penetrates the center of the impeller and axially extends to the stator. The central shaft comprises a spiral groove on the surface thereof. The spiral direction of the spiral groove corresponds to the rotational direction of the impeller.

Accordingly, when the centrifugal pump operates, air therein moves to the central shaft by compression of fluid and is expelled along the spiral groove, thereby decreasing pumping pressure, air binding, noise, vibration, and air erosion.

DESCRIPTION OF THE DRAWINGS

The invention can be more fully understood by reading the subsequent detailed description and examples with references made to the accompanying drawings, wherein:

FIG. 1 is a schematic cross section of a conventional centrifugal pump;

FIG. 2 is a schematic cross section of the centrifugal pump of a first embodiment of the invention;

FIG. 3 is a schematic top view of the impeller of FIG. 2; and

FIG. 4 is a schematic cross section of the centrifugal pump of a second embodiment of the invention.

DETAILED DESCRIPTION First Embodiment

Referring to FIG. 2, the centrifugal pump comprises a housing 5, an impeller 6, a stator 7, and a central shaft 8. The stator 7 is able to activate the impeller 6 rotating with the central shaft 4.

The impeller 6, stator 7, and central shaft 8 are disposed in the housing 5. The housing 5 comprises a top cover 50, an outer frame 52, and a base 54. An accommodation chamber is formed between the top cover 50 and the outer frame 52 for accommodating the impeller 6. The top cover 50 comprises a fluid inlet 501 and a fluid outlet 503. Fluid, such as water, flows into the centrifugal pump via the fluid inlet 501 and out of the centrifugal pump via the fluid outlet 503 along the rotational direction of the impeller 6. The fluid inlet 501, fluid outlet 503, and accommodation chamber of the housing 5 are connected to and communicated with one another. The base 54 is disposed opposite to the top cover 50. A sealed chamber is formed between the base 54 and the outer frame 52, in which the stator 7 is disposed.

The impeller 6 comprises a rotating portion 60 and a plurality of blades 61 disposed on the upper surface of the rotating portion 60. A gap exists between the impeller 6 and the top cover 50 and between the impeller 6 and the outer frame 52, allowing the fluid to flow through. At least one venthole 62 is axially formed to penetrate the rotating portion 60. As shown in FIG. 3, a plurality of ventholes 62 is formed in the impeller 6, preferably, uniformly distributed on the upper surface of the rotating portion 60.

The stator 7 is disposed under the impeller 6 and comprises a core 70 and a circuit board 71. The sealed chamber formed between the base 54 and the outer frame 52 of the housing 5 accommodates the core 70 and circuit board 71. The circuit board 71 is disposed on the base 54 and the core 70 is disposed on an axial extending portion of the base 54. The core 70 is electrically connected to the circuit board 71 and corresponds to the rotating portion 60 of the impeller 6, providing electromagnetic force to rotate the impeller 6 when applied with electricity.

The central shaft 8 penetrates the center of the impeller 6 and extends to the center of the core 70 of the stator 7. The impeller 6 rotates about the central shaft 8 when the core 70 is applied with electricity.

When the centrifugal pump operates, the fluid flows to the impeller 6 via the fluid inlet 501 and obtains kinetic energy by rotation of the impeller 6. The fluid then flows to the fluid outlet 503 by centrifugal force provided by the blades 61 of the impeller 6. Additionally, air under the rotating portion 60 is expelled via the ventholes 62 along the axial direction of the impeller 6 such that pumping pressure loss, air binding, noise, vibration, and air erosion are thus avoided.

Second Embodiment

Elements corresponding to those of the first embodiment share the same reference numerals, and explanation thereof is omitted for simplification of the description.

Referring to FIG. 4, the difference between this and the first embodiments is modification of the vent structure. Specifically, a spiral groove 80 is formed on the outer surface of the central shaft 8. The spiral direction of the spiral groove 80 corresponds to the rotational direction of the impeller 6. When the centrifugal pump operates, air under the rotating portion 60 moves to the central shaft 8 by compression of the fluid and is rapidly expelled along the spiral groove 80.

Structure, disposition, and function of other elements of the centrifugal pump of this embodiment are the same as those of the first embodiment, and explanation thereof is omitted for simplicity.

In conclusion, the aforementioned venthole and spiral groove can selectively be applied in a centrifugal pump to achieve the removal of air. Moreover, the aforementioned venthole and spiral groove can simultaneously be applied in the centrifugal pump, further enhancing the removal of air under the rotating portion of the impeller.

While the invention has been described by way of example and in terms of preferred embodiment, it is to be understood that the invention is not limited thereto. To the contrary, it is intended to cover various modifications and similar arrangements (as would be apparent to those skilled in the art). Therefore, the scope of the appended claims should be accorded the broadest interpretation so as to encompass all such modifications and similar arrangements. 

1. A centrifugal pump, comprising: a housing having an inlet, an outlet, and an accommodation chamber; an impeller disposed in the accommodation chamber and comprising at least one venthole penetrating the impeller; a drive member fixed to one side of the housing and corresponding to the impeller for providing electromagnetic force required for rotation of the impeller; and a shaft penetrating the center of the impeller and axially extending to the drive member.
 2. The centrifugal pump as claimed in claim 1, wherein the impeller further comprises a rotating portion and a plurality of blades, the venthole axially penetrates the rotating portion, and the blades are formed on a surface of the rotating portion.
 3. The centrifugal pump as claimed in claim 1, wherein the inlet, outlet, and accommodation chamber are communicated with one another.
 4. The centrifugal pump as claimed in claim 1, wherein a gap exists between the housing and the impeller.
 5. The centrifugal pump as claimed in claim 1, wherein the housing further comprises a cover and an outer frame, the accommodation chamber is between the cover and the outer frame, the inlet and outlet are formed and extend in the cover.
 6. The centrifugal pump as claimed in claim 5, wherein the outer frame surrounds the drive member, preventing a fluid from entering the drive member.
 7. The centrifugal pump as claimed in claim 5, wherein the housing further comprises a base opposite to the cover, and the drive member is fixed to the base.
 8. The centrifugal pump as claimed in claim 1, wherein the shaft comprises a spiral groove on the surface thereof.
 9. The centrifugal pump as claimed in claim 8, wherein the spiral direction of the spiral groove corresponds to the rotational direction of the impeller.
 10. A centrifugal pump, comprising: a housing having an inlet, an outlet, and an accommodation chamber; an impeller disposed in the accommodation chamber; a drive member fixed to one side of the housing and corresponding to the impeller for providing electromagnetic force required for rotation of the impeller; and a shaft penetrating the center of the impeller and extending to the drive member, wherein the shaft comprises a spiral groove on the surface thereof.
 11. The centrifugal pump as claimed in claim 10, wherein the spiral direction of the spiral groove corresponds to the rotational direction of the impeller, such that air under the impeller moves upward along the spiral groove.
 12. The centrifugal pump as claimed in claim 10, wherein the impeller comprises a rotating portion and a plurality of blades formed on a surface of the rotating portion.
 13. The centrifugal pump as claimed in claim 10, wherein the inlet, outlet, and accommodation chamber are communicated with one another.
 14. The centrifugal pump as claimed in claim 10, wherein a gap exists between the housing and the impeller.
 15. The centrifugal pump as claimed in claim 10, wherein the housing further comprises a cover and an outer frame, the accommodation chamber is between the cover and the outer frame, the inlet and outlet are formed and extend in the cover.
 16. The centrifugal pump as claimed in claim 15, wherein the outer frame surrounds the drive member, preventing a fluid from entering the drive member.
 17. The centrifugal pump as claimed in claim 15, wherein the housing further comprises a base opposite to the cover, and the drive member is fixed to the base.
 18. The centrifugal pump as claimed in claim 10, wherein the impeller comprises a venthole axially penetrating the impeller. 